Park Street Under is a sitcom set in a fictional bar in the Park Street subway station in Boston, Massachusetts. It was produced starting in 1979 by Boston television station WCVB-TV. This was a rare example in the United States of a half-hour sitcom produced by a local station during the 1970s. Park Street Under was an inspiration for the NBC sitcom Cheers, which was also set in a fictional Boston bar.

The cast included James Spruill, father of filmmaker Robert Patton-Spruill. The scripts were by Jonathan Stathakis and Stu Taylor.

Park Street Under is also the original name for the Red Line subway platform at Park Street, which is literally under the streetcar lines that became the Green Line.